Describe the structures that form the outside of a prokaryotic cell. Tell whether each structure is common to all prokaryotes

The structures that form the outside of a prokaryotic cell are the capsule, the cell wall and the cell membrane. Prokaryotes are unicellular organisms and they lack some organelles or other structures like the nucleus. The cell wall in this kind of cell is responsible for the shape of the organism and also serves as their protection. The plasma or cell membrane is responsible for separating the internal and external parts of the cells. Both of these structures are common in prokaryotes. Not all prokaryotes, though, have capsules.